Abstract

We tested the habitat preferences of Anguillaaustralis (shortfin) and A. reinhardtii (longfin) glass eels using circular tanks in an aquarium, containing four types of estuarine habitat (sand, mud, rocks/cobbles and seagrass). Shortfin eels either showed a tendency to occur in heterogeneous habitats, or in rocks/cobbles. Longfin glass eels showed a significant preference for rocks/cobbles in both experiments. Tests on shortfin and longfin glass eels in tanks with only rocks/cobbles available showed that eels were not clumped, indicating that individuals select habitat for re-settlement independently. Therefore, we assumed that the uneven distribution of glass eels observed in the habitat type experiments were the result of habitat preference. Given a choice of habitats in tank experiments, shortfin and longfin glass eels preferred habitats containing structure, and in particular, rocks/cobbles.